Universal Health Insurance and the Adequacy and Efficiency of Health Care This project will use comparisons between people just under and just over age 65 to measure how the availability of nearly universal health insurance for those over 65 affects the use of primary care versus Emergency Department services;the quality of health care services provided outside the hospital, and the treatment intensity and health outcomes of people admitted to the hospital for acute myocardial infarction. The results from this project will be directly policy-relevant as they will help to quantify the effects of insurance coverage (or lack of coverage) on the efficiency and efficacy of the health care delivery system for older adults. They will also provide valuable information for evaluating the costs of extending health insurance coverage to previously uncovered individuals. The findings will also provide new insights into the disparities in treatment of acute myocardial infarction patients across different patient groups, and how these disparities affect the health of these groups. PUBLIC HEALTH RELEVANCE: This project will use comparisons between people just over age 65 (nearly all of whom are covered by Medicare) and those just under age 65 (many of whom lack adequate health insurance) to learn how the availability of health insurance affects the use of Emergency Departments for non-urgent care, the rate of hospitalization for "preventable" causes, and the types of treatments provided to hospital patients admitted for heart attacks. These comparisons will help us to better understand the potential benefits and costs of expanding health insurance coverage.